European reusable rocket completes second cryogenic rehearsal

(SpaceEnergy) Europe's Themis reusable rocket stage demonstrator has completed a second cryogenic fuelling rehearsal in Sweden, advancing countdown procedures and automated ground operations for its planned methane-fuelled flight tests.

The European Space Agency (ESA) announced on 7 October that the rehearsal took place at Esrange Space Center on 29 September, involving prime contractor ArianeGroup and launch facility operator SSC Space.

The demonstrator was filled with liquid nitrogen cooled to approximately −200°C, allowing engineers to test its systems under representative cryogenic temperatures and pressures without using flammable propellants.

The exercise followed an initial rehearsal in July and included further testing of the final automated countdown sequence.

Teams also tested elements of robotic ground operations designed to support reusable rocket recovery and turnaround.

The robotic systems are intended to locate the vehicle after landing, establish connections and drain remaining fuel and oxidiser while personnel remain at a safe distance.

Themis is designed to land within a 20m by 20m area.

The demonstrator uses the Prometheus engine, developed to operate on liquid methane and liquid oxygen.

The programme forms part of the European Union-funded SALTO initiative, involving 25 industrial and research partners from 12 countries.

SSC Space said the latest rehearsal provided additional operational data and that teams were defining a window for the next test.

The second rehearsal represents a further ground qualification milestone, particularly for automated countdown and recovery operations. It did not involve engine ignition, flight or the loading of operational rocket propellants.